make scatter_hist variables configurable

Author: mikabr

_config.yml

@@ -0,0 +1,30 @@
+```{ojs}
+//| output: false
+
+Plot = import("https://esm.sh/@observablehq/plot@0.6.17")
+d = transpose(data)
+
+yaml = require("js-yaml")
+config_file = FileAttachment("_config.yml").text()
+config = yaml.load(config_file)
+
+distinct_cutoff = 10
+
+disc_types = (['string', 'boolean'])
+disc_filter = (config?.categorical_vars)
+  ? d => config.categorical_vars.includes(d.name)
+  : d => disc_types.includes(d.type) && d.numDistinct <= distinct_cutoff && d.numDistinct > 1
+disc_vars = vars.filter(disc_filter)
+disc_opts = new Map([['', null], ...disc_vars.map(d => [d.label ? d.label : d.name, d.name])])
+
+cont_types = (['integer', 'float', 'date', 'datetime', 'time'])
+cont_filter = (config?.numerical_vars)
+  ? d => config.numerical_vars.includes(d.name)
+  : d => cont_types.includes(d.type) && d.numDistinct > distinct_cutoff
+cont_vars = vars.filter(cont_filter)
+cont_opts = new Map(cont_vars.map(d => [d.label ? d.label : d.name, d.name]))
+
+x_val = config?.defaults?.x || cont_vars[0].name
+y_val = config?.defaults?.y || cont_vars[1].name
+color_val = config?.defaults?.color || disc_vars[0].name
+```

_plot-prep.qmd

@@ -1,17 +1,17 @@
 ```{ojs}
 //| panel: input
 
-viewof x_var = Inputs.select(cont_opts, {value: Array.from(cont_opts.values())[0], label: "X axis"})
-viewof y_var = Inputs.select(cont_opts, {value: Array.from(cont_opts.values())[1], label: "Y axis"})
-viewof color_var = Inputs.select(disc_opts, {value: Array.from(disc_opts.values())[1], label: "Color"})
+viewof x_var = Inputs.select(cont_opts, {value: x_val, label: "X axis"})
+viewof y_var = Inputs.select(cont_opts, {value: y_val, label: "Y axis"})
+viewof color_var = Inputs.select(disc_opts, {value: color_val, label: "Color"})
 ```
 
 ```{ojs}
 default_color = d3.schemeCategory10[0]
 plt_color = color_var || default_color
 
-all_vars = cont_vars.concat(disc_vars)
-channels = Object.fromEntries(all_vars.map(k => [k[1], k[1]]))
+all_vars = [...cont_vars, ...disc_vars]
+channels = Object.fromEntries(all_vars.map(k => [k.name, k.name]))
 
 viewof scatter = Plot.plot({
   style: { fontFamily: "var(--sans-serif)" },

_scatter_hist.qmd

@@ -13,6 +13,8 @@ description: |
 
 {{< include _load-data.qmd >}}
 
+{{< include _plot-prep.qmd >}}
+
 {{< include _scatter_hist.qmd >}}
 
 <!-- {{< include _scatter.qmd >}} -->